Sugar dissolves in water because energy is given off when the slightly polar sucrose molecules form intermolecular bonds with the polar water molecules. The weak bonds that form between the solute and the solvent compensate for the energy needed to disrupt the structure of both the pure solute and the solvent.

Is sugar dissolving in water physical or chemical?

Dissolving sugar in water is a physical change because sugar molecules are dispersed within the water but the individual sugar molecules are unchanged.

Why did sugar dissolve in water?

The sucrose molecules are attracted to one another by positive and negative polar areas. The polar water molecules attract the oppositely charged polar areas of the sucrose molecules and pull them away, resulting in dissolving.